Determination of iodine content in milk and food supplements by inductively coupled plasma mass spectrometry (ICP-MS)

Abstract

The determination of iodine in milk and food supplements by inductively coupled plasma mass spectrometry (ICP-MS) was investigated. Several parameters of the equipment were optimized automatically such as power of radio frequency, nebulizer gas, and voltage of ion lens. Iodine was extracted from samples by using 2% HNO3 with ultrasonic at 80ºC. Sample solutions were adjusted to the pH of 9÷10 by using ammonium hydroxide, and then filtered by using a 0.45 µm membrane before being analyzed by means of ICP-MS. The method has good repeatability and high recovery efficiency that are suitable for the determination of iodine in milk and food supplements.